1. Field of the Invention
The present invention relates generally to gas turbine combustors into which steam is injected and steam injected gas turbines including the gas turbine combustors. More particularly, the present invention relates to a gas turbine combustor and a steam injected gas turbine including the gas turbine combustor that can be applied to a variable heat to power cogeneration system that varies an amount of injection steam to thereby change an output ratio of heat (steam) and power.
2. Description of Related Art
The variable heat to power cogeneration system injects part of steam (heat) generated by exhaust heat of a gas turbine into a gas turbine combustor to thereby increase power generation and improve thermal efficiency. By varying the amount of injection steam for the gas turbine combustor, the variable heat to power cogeneration system can change a ratio of steam (heat) and power. The system can change the heat to power ratio according to the ratio of heat demand to power demand and is greatly expected as a high efficiency dispersed power source with low energy loss.
JP-UM-A-4-25967 discloses a gas turbine combustor into which steam is injected, such as the gas turbine combustor in the variable heat to power cogeneration system. The gas turbine combustor includes two types of steam jet nozzles in order to maintain stable combustion and to reduce nitrogen oxide (NOx) even with a large amount of steam supplied, specifically, a multihole inside-combustor-casing steam jet nozzle and a dilution-zone steam jet nozzle. The inside-combustor-casing steam jet nozzle supplies steam into an air flow path having an annular cross section formed between a combustion liner and a combustor casing. The dilution-zone steam jet nozzle supplies steam directly into a dilution zone inside the combustor from part of dilution air holes formed in the combustion liner.